I Love These Headphones...The NAD VISO HP50

NAD VISO HP50 ($299)
For those of you looking for a great all-around headphone, run, don't walk, to your nearest NAD dealer and get one...right now.

Not convinced yet? Okay, I'd be happy to go on for a little while about why this headphone is simply a game changer. We'll start with Paul Barton...

You may have read my recent article on the work done by Sean Olive et. al. at Harman Intl. on developing a new headphone target response curve. In it, I describe the great lengths to which this research team has gone doing the detailed work needed to carefully develop a pleasing headphone response by both objective and subjective means. This very careful study is slowly but surely coming to the conclusion that headphones should sound like speakers in a room, and a target response curve for headphones is slowly coming to light. Dr. Olive is proceeding with this very methodical work in an effort to conclusively establish a new headphone target response curve for the audio engineering community. Much of Olive's work and methods rest on research done at Canada's National Research Council in the 1980s, which was aimed at finding pleasing loudspeaker target response curves. Floyd Toole lead the team of researchers at the time; both Sean Olive and Paul Barton were involved with the project.

While Olive's current work is designed to bring a new standard into the body of knowledge for headphone designers and must be extremely methodical toward that end; Barton is under no such onus in his work designing product for PSB and NAD. His job is simply to make a good sounding headphone. That's not to say Barton doesn't do careful and methodical researchhe certainly does and, in fact, has participated in some recent strides developing a better ear-canal simulator that improves the accuracy of high-frequency measurements for headphonesbut it does mean that he can make some assumptions about headphone response (like they should sound like good speakers in a good room) and move directly toward finished product. Such is the difference between pure research and product development.

Barton makes these assumptions with a lot of solid information in his head, however. First, he knows one heck of a lot about what a good speaker sounds like in a good room. And second, he has an expert grasp on acoustic couplers and how to measure headphones. Combine these two skills together and you've got a potent brew for developing some great sounding cans. I've spent quite a bit of time picking his brain on his thought process, and the development of PSB and NAD's "Room Feel" technology.

Basically, if you take a direct radiating speaker that measures flat in an anechoic chamber and put it in a room, you'll find that it will have a significantly warmer sound. This happens because as frequency gets lower, the speakers radiate more omni-directionally, and therefor, the sound power content in the room as a whole gets stronger as frequency get lower. While this increase in low frequency response is somewhat decoupled from our perception of the sound from the speakers, it remains an important part of our impression of what a good speaker system sounds like.

In headphones, of course, there is no "room response" in the equation, and designers have typically either attempted a flat response into the lowest notes or added a big bass hump to satisfy bass lovers, but no real thought has gone into making a headphone response match that of the typical low-frequency boost heard in a good room. Here Barton's long expertise in matters acoustic come into play, and he has developed a very well reasoned headphone target response curve that takes into consideration low-frequency room gain and a number of other characteristics of a speaker's sound in a room, which has been labeled "Room Feel" by the company.

Paul and I both await Sean Olive's final headphone target response curve with baited breath. He because he's pretty darn sure the NAD VISO HP50 is right on target, and I because after hearing Paul's latest take on "Room Feel" have got to believe that tuning headphones to sound like good speakers in a good room leads to a darned good sounding headphone, and I'd love to have a better compensation curve for my headphone measurements than the one I currently use.

I'm having a hard time deciding whether or not I get hd600s for home use and keep using my cals in the workplace and elsewhere, or if I should get something like the hp50 and use it for everything. What would you do? Have better quality at home but lower quality during the working day? Or just get one pair of non-open headphones to use consistently. Nice review as always!

Of course you wouldn't do it since this is your job and hobby. We wouldn't want you to stick with this as the last pair because there would be no more reviews and no more innerfidelity LOL... But just being able to say that you can live with this one is enough for me to buy a pair.

The HD600 is an excellent headphone, and will respond very well to an increasingly good front end and amp before it. Resolution and finesse will be superior to the HP50. But, the HP50 will have a somewhat better tonal character overall---punchier bass, a bit more lively---relative to the more laid back sound of the 600. It doesn't seem to improve as much with better front ends, and will likely be more pleasurable directly out of a smartphone.

I was looking forward to your review. It was both informative and entertaining!

Question: I read somewhere in Head-fi that the HP50 leaks sound (hence, disturbs others). I would have thought that if the heaphone isolates well, this would work both ways. Would you be able to verify?

Great review as always Tyll! I'm considering purchasing these to take over as the sole headphones for my portable rig. My budget is about £500/$500 (the UK does not do well on price conversions for electronics!), but I can't seem to find anything that looks more suitable than these even with a couple of hundred quid breathing space above them. Do you have any other recommendations for high end, portable headphones for within that budget, and how do the HP50s compare to the Amperiors? Thanks!

I believe there are several elements to a "good sounding headphone" (if that even means anything, since people's hearing rates differently + subjective preferences), but the main 3 would be:

1: the quality and technology of the driver itself

2: the voicing/frequency response tuning of the driver

3: the chamber/enclosure/casing of the driver. And perhaps the cloth on top together with the distance/angle to the ear and pad characteristics.

....all those combined (dependant on each other)

But I highly doubt the experience between speakers and headphones could ever be identical. Maybe thats a good thing anyway. Sometimes intimacy and detail is wanted over an open, expansive live feeling.

Out of curiosity I saw the phiaton bridge MS 500 measurements in pdf, how do they sound Tyll? quite intrigued by the design.

Thanks for this review, Tyll. It certainly has put this 'phone on my radar. The price is right for such praise and I am very interested in Doc Olive's work.

I'd been considering the Mr. Speakers Alpha Dog and the perennial favorite Sennheiser HD 600. Now this little fella comes along. I'll wait the next month or two and see if you post an Alpha review and do some research on the NAD. I find sealed headphones very practical and this one really does have the whole package - sound good, don't scream "audio dork" if you wear them in public, half the price of lots of other "entry level" phones.

I was waiting for Tyll's short comparison on these against the m500 too since not too many have heard both at the same time. The people that have heard both are also not known to me and I am not sure whether to trust them or not since I haven't seen any other reviews of any other cans from them yet for me to be able to gauge their tastes and similarity to my hearing.

I have a pair of Barton's PSB M4U-1 headphones, and think they're fabulous. The online reviews of NAD phones report they're very, very similar to the PSB phones, which is no surprise - and all of the reviews rate them very highly. Tyll, you've heard the active NR M4U-2, but why not give the passive M4U-1 a try, given how much you like the NAD phones?

Wow these measure very nice. Low distortion, good frequency response and square wave. I guess the room feel may also have something to do with the CSDs and how much delay is put into the lower mids to bass? Like the way speakers have some reverb/time delay in the room?

I assume these are not quite as good as the PSB's, which also feature "RoomFeel". Why would Paul Barton design something for NAD that trumps his own cans? Or is it just a different sound, that you happen to prefer?

...well, I found the M4U1 a bit too strident. If you look at the impulse response and 300Hz square wave from the M4U2 passive, you'll see what I mean. While I think both cans come close to the proper EQ, I do think the HP50 does so in a more refined way.

I knew that if Tyll was not getting all hyped about the Tascam TH-02, there had to be some other headphone drawing his attention about headphones elsewhere. This has got to be the biggest revolution yet in the sweet spot price region of headphones. The graphs seem to say NAD VISO HD50 is worth all the hype because it measures like a dream. One set of graphs goes on to show it as a little more treble oriented than Innerfidelity's datasheets, yet still sublimely linear, nonetheless. As an added bonus, a waterfall chart of the response of this headphone is included which is equally impressive: http://stereos.about.com/od/accessoriesheadphones/ss/NAD-Viso-HP-50-Meas...

Hey Tyll thanks for reviewing a great closed can like i asked :). If i can ask one more favor how do these and the Sennheiser HD-650 compare? Remembering the 650 and hearing about these they seem to share some simmilarities.

Both are kind of warm headphones. But otherwise there's a good bit of difference. The HP50 won't get much better with more expensive amps. The 650 is a headphone that likes high-output impedance tube amps (Woo WA3, Bottlehead Crack) to my ears. They'll be somewhat more refined sounding as well. It's a sealed can, a damned good one, but it's not an open headphone and isn't going to get the kind of air the 650 has.

I like the HD 518. Have you heard it Tyll? I bet it compares in EQ to this phone. Would be good to see it reviewed and measured, since it is a very affordable, well built, and great sounding headphone!

Tyll I have to admit that I'm confused by your wall of fame. The momentum are now retired, whereas before they were your favorite of the bunch. While I certainly understand now preferring another headphone I'm not sure why all of a sudden that removes the momentum from the list...

Looking at it now it indicates that now all the sudden you actually like them less than those others still on the list. So did hearing the NAD all the sudden male you hate the momentum? Why not just put them second behind the NAD?